Like you said, it would unfortunately be unmaintainable, requiring a fork of CPython. Aggressive optimizations like this could go into pypy, but IMO CPython is

Like you said, it would unfortunately be unmaintainable, requiring a fork of CPython. Aggressive optimizations like this could go into pypy, but IMO CPython is still trying to be a "reasonably readable" reference implementation. I think the time is currently best spent trying to push more of the work back into native code, extending the simple filtering that's in there now to also handle mutation (similar to jq), reducing the amount of back-and-forth with the interpreter.